Plaster-board.



S. M. FORD.

PLASTER BOARD.

APPLICATION FILED AUG-9, 1915.

1,171,421, Patented Feb. 15,1916.

f'nv'e 721%?" 5170215 Frfl SILAS M. FORD, OF ST. PAUL, MINNESOTA.

PLASTER-BOARD.

Specification of Letters Patent.

Patented net. s, 1916.

Application filed August 9, 1915. Serial No. 44,508.

fastened to the" studding or beams of struc-' tures to constitute afoundation for plaster.

Among the objects of the invention is to provide a plaster board offlexible sheeting, preferably waterproofed, which is corrugated to formlath like projections and intermediate depressions so that there will beair spaces beneath the plaster at every ppint of its surface, whereby toprovide sound deadening and heat insulating spaces under the entiresurface of the plaster.

Further objects are to provide a lath board which will be resilientenough to yield to the expansion of the plaster so as to prevent thesame from cracking and which has reinforcing strips embodied therein tohold the corrugations to form.

Nith these ends in View the invention consists in the construction,combination, and arrangement of parts hereinafter described and claimed.

In the accompanying drawings showing an embodiment of the invention,Figure l is a perspective view of a fragment of plas ter board embodyingand shown secured to a backing board; Fig. 2 is a perspective view ofthe same without the backing; and Fig. the board as shown in Fig. l.

The plastering board of the presentinvention is made of a sheet rial,preferably waterproofed paper, such as rope stock surfaced orimpregnated with asphalt or the like. The sheet is bent or molded underpressure to form. corrugations or alternate lath projections anddepressions having the cross sectional shape shown in Fig. 3 of thedrawings. As here shown every other lath projections is of keyed lathshape with its sides inclined downwardly and inwardly toward each otherat an acute angle, such as the projections 2 shown in the drawings,while alternatingv with these projections are lath projections 3 havingtheir sides inclined outwardly away from each other at an obtuse angleto the face of the lath projection. Between the lath prothe presentinvention 3 is an end view of of flexible mate;

jections are depressions or recesses 4 located in the angle between theinwardly inclined sides of the projections 2 and the outwardly inclinedsides of the adjacent projections 3. Beneath each keyed lath projection2 is a triangular air space 5 contracting toward the bottom, and beneatheach projection 3 is an air space 6 spreading or widening toward thebottom.

To hold the lath projections to form, that is to prevent them from beingflattened or crushed in use, as well as to provide means ing stripsextending transversely across the corrugations at spaced intervals. Inthe drawings I have shown the reinforcement strips in the form of strips7 piercing and passing-transversely through the sides of thecorrugations beneath the lath faces thereof. As a further or substitutemeans of holding the strips to form I have in Figs. 1 and 3 shown thecorrugated board secured to a backing sheet 9 by means of staples 8.which. from slipping help to hold the plaster lengthwise along thedepressions between the lath projections.

NVhen the plaster is laid upon the board it will cover the projections 2and 3 and fill in the angular depressions or recesses 4 between theprojections.

shape shown in the drawings the spaces 6 beneath the projections 3extend entirely under the recesses 4 and theplaster laid therein, asbest shown .for preventing the plaster from slipping,'l prefer to embodyin it one or more re-inforc-,

An important fea I ture of the plaster board is that by giving thecorrugations the in Fig. 3, as well as under the projections 3,

while the triangular spaces 5 not only underlie the projections 2 butextendpart way over the adjacent recesses 4 and overlap the ends of thespaces 6, so that there is an insulating air space or! entire surface ofthe plaster.

I claim: i

1. A plaster board comprising a sheet of flexible material corrugated toform lathlike projections and intermediate plaster receiving recesses,every other projection being formed in the shape of a keyed lath withinwardly inclined sides, and the intermediate projections being formedwith outwardly inclined sides, the inclination of the sides being suchthat the air spaces beneath said prof the same.

air spaces under the 2. A plaster board comprising a sheet of flexiblematerial corrugated to form lath like projections and intermediateplaster receiving recesses, every-other projection having inwardlyinclined sides and the intermediate projections having outwardlyinclined sides, the inclination of the sides being such that the airspaces beneath the outwardly inclined projections Will underlie theplaster receiving recesses at the sides of said projections.

3. A plaster board comprising a sheet of flexible. material corrugatedto form lathlike projections and intermediate recesses,

